[php] Forcing to download a file using PHP

I have a CSV file on my server. If a user clicks on a link it should download, but instead it opens up in my browser window.

My code looks as follows

<a href="files/csv/example/example.csv">
    Click here to download an example of the "CSV" file
</a>

It's a normal webserver where I have all of my development work on.

I tried something like:

<a href="files/csv/example/csv.php">
    Click here to download an example of the "CSV" file
</a>

Now the contents of my csv.php file:

header('Content-Type: application/csv');
header('Content-Disposition: attachment; filename=example.csv');
header('Pragma: no-cache');

Now my issue is it's downloading, but not my CSV file. It creates a new file.

If you are doing it with your application itself... I hope this code helps.

HTML

In href -- you have to add download_file.php along with your URL:

<a class="download" href="'/download_file.php?fileSource='+http://www.google.com/logo_small.png" target="_blank" title="YourTitle">

PHP

/* Here is the Download.php file to force download stuff */

<?php
    $fullPath = $_GET['fileSource'];
    if($fullPath) {
        $fsize = filesize($fullPath);
        $path_parts = pathinfo($fullPath);
        $ext = strtolower($path_parts["extension"]);

        switch ($ext) {
            case "pdf":
                header("Content-Disposition: attachment; filename=\"" . $path_parts["basename"]."\""); // Use 'attachment' to force a download
                header("Content-type: application/pdf"); // Add here more headers for diff. extensions
                break;

            default;
                header("Content-type: application/octet-stream");
                header("Content-Disposition: filename=\"" . $path_parts["basename"]."\"");
        }

        if($fsize) { // Checking if file size exist
            header("Content-length: $fsize");
        }
        readfile($fullPath);
        exit;
    }
?>

A previous answer on this page describes how to use .htaccess to force all files of a certain type to download. However, the solution does not work with all file types across all browsers. This is a more reliable way:

<FilesMatch "\.(?i:csv)$">
  ForceType application/octet-stream
  Header set Content-Disposition attachment
</FilesMatch>

You might need to flush your browser cache to see this working correctly.

This cannot be done reliably, since it's up to the browser to decide what to do with an URL it's been asked to retrieve.

You can suggest to the browser that it should offer to "save to disk" right away by sending a Content-disposition header:

header("Content-disposition: attachment");

I'm not sure how well this is supported by various browsers. The alternative is to send a Content-type of application/octet-stream, but that is a hack (you're basically telling the browser "I'm not telling you what kind of file this is" and depending on the fact that most browsers will then offer a download dialog) and allegedly causes problems with Internet Explorer.

Read more about this in the Web Authoring FAQ.

Edit You've already switched to a PHP file to deliver the data - which is necessary to set the Content-disposition header (unless there are some arcane Apache settings that can also do this). Now all that's left to do is for that PHP file to read the contents of the CSV file and print them - the filename=example.csv in the header only suggests to the client browser what name to use for the file, it does not actually fetch the data from the file on the server.

Or you can do this using HTML5. Simply with

<a href="example.csv" download>download not open it</a>

To force download you may use Content-Type: application/force-download header, which is supported by most browsers:

function downloadFile($filePath)
{
    header("Content-type: application/octet-stream");
    header('Content-Disposition: attachment; filename="' . basename($filePath) . '"');
    header('Content-Length: ' . filesize($filePath));
    readfile($filePath);
}

A BETTER WAY

Downloading files this way is not the best idea especially for large files. PHP will require extra CPU / Memory to read and output file contents and when dealing with large files may reach time / memory limits.

A better way would be to use PHP to authenticate and grant access to a file, and actual file serving should be delegated to a web server using X-SENDFILE method (requires some web server configuration):

• X-SENDFILE is natively supported by Lighttpd: https://redmine.lighttpd.net/projects/1/wiki/X-LIGHTTPD-send-file
• Apache requires mod_xsendfile module: https://tn123.org/mod_xsendfile/ On Ubuntu may be installed by: apt install libapache2-mod-xsendfile
• Nginx has a similar X-Accel-Redirect header: https://www.nginx.com/resources/wiki/start/topics/examples/xsendfile/

After configuring web server to handle X-SENDFILE, just replace readfile($filePath) with header('X-SENDFILE: ' . $filePath) and web server will take care of file serving, which will require less resources than using PHP readfile.

(For Nginx use X-Accel-Redirect header instead of X-SENDFILE)

Note: If you end up downloading empty files, it means you didn't configure your web server to handle X-SENDFILE header. Check the links above to see how to correctly configure your web server.

This means that your browser can handle this file type.

If you don't like it, the easiest method would be offering ZIP files. Everyone can handle ZIP files, and they are downloadable by default.

Here is a more browser-safe solution:

    $fp = @fopen($yourfile, 'rb');

    if (strstr($_SERVER['HTTP_USER_AGENT'], "MSIE"))
{
    header('Content-Type: "application/octet-stream"');
    header('Content-Disposition: attachment; filename="yourname.file"');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header("Content-Transfer-Encoding: binary");
    header('Pragma: public');
    header("Content-Length: ".filesize($yourfile));
}
else
{
    header('Content-Type: "application/octet-stream"');
    header('Content-Disposition: attachment; filename="yourname.file"');
    header("Content-Transfer-Encoding: binary");
    header('Expires: 0');
    header('Pragma: no-cache');
    header("Content-Length: ".filesize($yourfile));
}

fpassthru($fp);
fclose($fp);

Configure your server to send the file with the media type application/octet-stream.

Nice clean solution:

<?php
    header('Content-Type: application/download');
    header('Content-Disposition: attachment; filename="example.csv"');
    header("Content-Length: " . filesize("example.csv"));

    $fp = fopen("example.csv", "r");
    fpassthru($fp);
    fclose($fp);
?>